LIZ JONES: Like Lilly Jay, I was publicly cuckolded by my husband and fought back. That's why I know exactly what will happen now to Wicked Ariana Grande and her ginger nut new love Ethan Slater

It is Wicked. Really, really Wicked.

We all know of men who can't control themselves. That after their wife has given birth - and when the husband is no longer the infant in the family - they toddle off to pastures new.

But for a woman to aid a man in doing this to another woman is, well, as I say, Wicked.

To recap. Ariana Grande, a 31-year-old pop star famed for her high voice and even higher ponytail, met an actor ginger nut called Ethan Slater, 32, on the set of her latest film, a musical based on the Wizard Of Oz called, well, you guessed it. He plays a munchkin: not a huge leap.

They start 'growing closer' while both married to other people, Grande to Dalton Gomez, an estate agent, and Slater to Lilly Jay, a brilliant clinical psychologist specialising in women's mental health. Both Slater and Grande filed for divorce last year, within days of each other, and three days later announced their relationship.

Slater's wife of six years has spoken of the 'darkness' of being so publicly cuckolded. Watching him promote the musical on red carpets around the world is, she says, a painful reminder of 'the public downfall of my marriage'. He of course claims they were separated when he met the Hollywood star. To cap it all, Jay and Slater have a young son - she almost died giving birth to him - who was less than a year old as this happened.

Now, Jay has written an essay published in The Cut this week - so much more high-brow and considered than canoodling on a carpet - saying how she noted that during her pregnancy she had 'never felt happier nor more aware of how precarious happiness could be. I survived preeclampsia and finally, our family was whole. Mine is a story of worrying in the wrong direction,' she wrote.

Yeah. Take your eye off the ball and the man will soon score a spectacular own goal.

I kind of love Jay because she hasn't taken this lying down.

In interviews, she has branded the popstrel to be 'not a girl's girl' and that 'my family is just collateral damage'.

To be humiliated in public is horrendous, and I should know. My husband of three years had numerous affairs, both before and after we were married. I only found out by opening my laptop and seeing he had lazily left his email queue open. And there they were, hundreds of emails, the most recent arranging to meet up in New York, on a trip paid for by me. 

I stood up and found the camera I'd given him to take travelling in India (he'd whined it was 'really heavy, and the strap will make me hot'), and scrolled through photos of him in bed with a blonde, cuddling her on a balcony, which he hadn't bothered to delete. Her delicate wrist was adorned with friendship bracelets. Well, she was no friend to the sisterhood!

I'd given my husband a beautiful home, a leg-up in his career. I was funny, generous, warm, well-groomed and expensively dressed and yet still he cheated.

Lilly Jay gave her husband an even greater gift: a child. Women tend to blame ourselves but, Lilly, I am telling you now that his desertion is not your fault. It's about his weakness. And it is also about Grande's predatory behaviour; because as the big star she holds all the power. I'd imagine as a lowly cast member making moves on the star would get him sacked. And is she certain of his motives? Look at this ginger nobody's new-found level of fame.

My husband seemed proud of his prowess. While he begged me to forgive him, he still, in an interview in The Guardian, spoke without regret of his infidelity: I suppose it buffed his 'bad boy' novelist kudos.

Of course, people fall out of love. But as a betrayed wife, I couldn't understand why he would say this. As Emma Thompson says so movingly to her errant husband in Love, Actually, 'You've made the life I lead foolish.'

Once the news of our marriage breakdown made the front page, men would look me up and down and think: 'Hmm, there must be something wrong with her.' Women, though, would come up to me on the street or check-out counter and say, 'You are well rid.'

The best thing about a marital breakdown being played out in public? You can, like Jay, wreak delicious revenge. I published the emails between my husband and the woman I gave a highly insulting name. Oh, and I published her real name, too: it's Daphne. And the name of the next one (I stupidly took my ex back), Kavita, a work experience girl he met at a literary festival.

Of course, both women told me they had no idea we were still a couple, as my husband had lied.

But women need to be more mindful of the lives they destroy - they could have easily googled us to find out we were still together - and remember, if he can cheat on me, he can cheat on you, too.

Will Ariana and the ginger nut go the distance? He will benefit financially, but only if they get married. While she clearly believes she is catnip to men (as she sings in Let Me Love You: 'Now I'm out here single, I don't really know what's next… I'm a chill and sit back, I know they will be coming from the right and the left'), I can't see her residing long in the hearts of her very young fans, starry-eyed idealists all.

I stalked Daphne on social media for years. When I told my by-then ex-husband she had just had a baby. 'Has she? I haven't thought of her in years, didn't know she was on Facebook,' he said. These infatuations, potted in the compost of carnal desire, rarely thrive.

Lilly Jay. One day, he will regret that he lost you, and become a bitter loveless failure no woman will touch with a barge pole.

I speak from experience.